My winter storage prep was always 1) change the oil, 2) full tank of gas with stabilizer, 3) connect battery tender. The tire flat spots always went away within 5 miles of my first spring drive. Never a problem in the 5 years I stored the car over winter.
It's true that the cold temperatures affects summer tires, and everything I've read for the PS4S suggests giving the tires 24 hours to "warm up" if they've been subjected to temps less than 20* F.